Wire-wound tangential telemetric transmitter



June 3, 1952 c. R. MlKOLlC WIREWOUND TANGENTIAL TELEMETRIC TRANSMITTER Filed March 15, 1950 Patented June 3, 1952 WIRE-WOUND TANGENTIAL TELEMETRIC TRANSMITTER Charles R. Mikolic, Milwaukee, Wis., assignor to Allis-Chalmers Manufacturing Company, Milwaukee, Wis.

Application March is, 1950, Serial No. 149,725

6 Claims. 1

This invention relates in general to telemetric systems and in particular to resistance type transmitters used in such systems.

Some prior art transmitters of this type are constructed of two arcuate contact segments disposed 180 degrees apart on the circumference of a circle, with contact buttons disposed along the circumference between the arcuate segments. A resistor is connected to the contact buttons and a plurality of brushes connected to a telemetric receiver alternately engage the contact segments and the contact buttons as relative rotation takes place between the brushes and the resistor as sembly.

Another type of telemetric transmitter comprises turns of wire wound on a core of varying or stepped cross section to produce a nonuniform distribution of the resistance of the wound wire on the core. An additional type of transmitter comprises a plurality of turns of wire of varying cross sections and/or different resistivities wound upon a. suitable core.

The first transmitter described above has the disadvantages that the use of contact buttons make the transmitter very expensive and that, because of the gap between the end of a contact segment and the adjacent contact button, as the brushes transfer from the contact segment to the contact button an objectionable burning or areing occurs about the brushes.

The stepped type transmitter is also expensive because of the diificulty involved in ac curately winding the wire about the irregularly shaped core, while the necessity of splicing together wires of different cross sections and/or different resistivities in the last type transmitter described above renders its manufacture unduly costly.

These disadvantages can be overcome by utilizing a transmitter-which is composed of wire of uniform cross section uniformly distributed upon a core of essentially uniform cross section and which retains the accuracy of the above described transmitters at a substantial reduction in cost. One method of achieving such construction is to embed two contact sections in the core on which the resistance wire is to be wound for conductively joining some of the turns of the wire to the contact sections after the wire is wound on the core.

It is, therefore, an object of this invention to provide a telemetric transmitter employing contact sections and turns of resistance wire in which the contactmaking brushes ofthe transmitter are in continuous engagement with the turns of wire.

It is a further object of this invention to provide a simply constructed, inexpensive, and rugged resistor type telemetric transmitter.

Objects and advantages other than those above set forth will be readily apparent from the following detailed description when read in connection with the accompanying drawing, in which:

Fig. 1 is a view partly in axial cross section and partly in elevation of the preferred embodiment of the invention;

Fig. 2 is a sectional view taken along line 11-11 of Fig. 1;

Fig. 3 diagrammatically illustrates the arrangement and circuits of a telemetric system embodying the preferred form of this invention; and

Fig. 4 diagrammatically illustrates the arrangement and circuits of a telemetric system embodying an alternate form of this invention.

As shown in Fig. 1, the transmitter of this invention may be mounted on a U-shaped member 5 provided with an opening into which is fitted a threaded collar 1 secured to member 5 by lock nuts 8 and 9. An additional lock nut H is provided on collar 1 to clamp the transmitter assembly to a suitable mounting place such as a switchboard l2.

A rotatable shaft l3 extends through collar 1 and is journaled therein. Shaft I3 is provided with a head portion I4 extending into an opening in a support [5. The support is rigidly clamped against a shoulder portion 2| of shaft l3 by a screw l8 and a washer l9.

An annular core 25 for a winding of axially disposed turns is provided and at least when the winding is made from wire having a low dielectric strength between turns, core 25 may be composed of any suitable insulating material having any suitable shape, such as the rectangular shape shown. I

A member of any suitable conducting material in the form of a wire or an arcuate bar 26 is inserted in a slight recess formed in core 25 through a degree angle. A second arcuate conductive bar 21 is inserted in a second recess formed in the core through a 90 degree angle diametrically opposite the recess containing bar 26. Bars 26 and 21 are preferably dimensioned so as to seat in the recesses below the remainder of the outer surfaces of core 25, and are secured to core 25 by cement.

Core 25 is Wound with a single winding 28 consisting ofa plurality of axially disposed turns of wire of uniform cross section, as shown in Fig. 2, and is so wound as to have a uniform numberof turns thereon per unit of peripheral length. The

segment of the winding 28 which rests on bar 26 is conductively joined thereto by any suitable known means, such as high temperature soldering, to thereby form a low resistance connection between the turns of the 90 degree winding segment resting on bar 26. Similarly, the segment of winding. 28 resting on bar 21 is conductively joined thereto to form a second low resistance connection between the turns of this second 90 degree segment. Core 25 is concentrically attached to support l by any suitable means such as air drying cement 24 or a coating of vitreous enamel. Rotation of shaft I3 in accordance with an indication to be transmitted causes rotation of support l5 and core 25 within member 5.

If desired, core 25 may be composed of a conductive material, if the turns of winding 28 and bars 26 and 21 are suitably insulated from the core 25.

A plurality of contact making brushes make contact with bared portions of the turns of winding 28 when support l5 and core 25 rotate. In the embodiment illustrated, four contact making mechanisms in the form of a pair of rollers 20 and a second pair of rollers3il are-shown, each roller being spaced 90 degrees from its adjacent rollers. The four rollers and their assemblies are similar and, therefore, the elements of only one assembly are identified by reference numerals to avoid unduly crowding the drawing. Roller 20 is composed of any suitable conducting material and is freely rotatable on a pin l0 carried by a fork 29. Fork 29 is in turn pivotally mounted on a pin 3[ carried by asecond fork 32.

All forks 32 are secured by their studs" 33 and locating pins [6 to a common base 34 of suitable insulating material forming a supporting means therefor. Each stud 33" is tappedto receive a terminal screw 35. Stud 33, forks 29, 32 and pins l6, 3| are of suitable conducting material so as to freely conduct current from roller 20 to terminalscrew 35. Each roller is biased by aspring 36 to maintain the rollers in good electrical contact with the bared surface of winding 28' at all times.

A cylindrical projection 4! of suitable insulating material is centrally mounted on. base 34. Projection 4! is provided with a collector rin 42 set in a recess about the periphery of projection 4| and conductively connected to a terminal screw 43 by a bar 44 and a terminal stud 45. A conductive rod 46 terminating in a contact face 41 at one end extends axially through the center of projection 4| and is connected to a terminal stud 43 and a terminal screw 49 at its other end.

A flexible contact finger 52 having a contact button 53 in contact with collector'ring 42 is secured by a screw 54 to support l5, and a second flexible contact finger 55 having a contact button 55 in engagement with contact face 41 is secured by a screw 51 to support I5. Contact fingers 52 and 55 are connected to bars 26 and 21 and their associated turns of winding 23 by conductive connectors 58, 59, respectively, so that when a source'of electrical energy is connected to terminal screws 43, 49, the resistor transmitter comprising winding 28 and bars 26, 21 is continuously supplied with current as relative rotation takes place between the rollers and winding 28.

The entire assembly may be housed within a casing 22 and provided with a cover 50 securely fitted against a shoulder 31 of base 34 to protect the assembly from foreign matter and accidental contact with its terminals.

Fig. 3 diagrammatically illustrates the arrangement and connections of the preferred em bodiment of the transmitter of this invention in conjunction with a telemetric system. Brushes 20 are connected to the stator coils 62 of a receiver of any suitable type such as one employing a permanent magnet rotor 63. Brushes 39 are. connected to a second pair of receiver stator coils 64 displaced electrical degrees from coils 62. Rotor 63 is mounted on a shaft 65 connected with any device to be remotely actuated. Shaft 65 may serve, for example, to actuate a device requiring substantially no torque, such as a pointer 66 to be moved over an indicating dial 61. Shaft 65- may also be used to drive a device requiring exertion of-a substantial torque, such as a valve 68 for controlling the flow of fluid through a'conduit.

The transmitter is energized from any suitable source such as a battery 69 connected to bars 26 and 21 in the manner hereinbefore described. In the position shown in Fig. 3, brushes 30 connected to receiver coils64 are connected directly across battery 69, while the brushes 26 are at equipotential points on winding .128 and therefore no current flows through coils 62. Under these conditions, rotor 63 aligns itself'with the field produced by coils 64and assumes the position shown.

Rotation of shaft 13 in accordance with an indication to be transmitted rotates core 25 and winding28xunder the rollers 20, 30 and varies the resultant magnetomotive force in the receiver. As long as the pair of brushes connected to coils 64 remain in contact with the turns of winding 28 short circuited by bars 26 and 21, the magnetomotive fcrce'of coils 64 remains constant in magnitude, while rotation of winding 28 with respect to the brushes connected to coils 62 causes the current through coils 62 to increase in a direction dependent upon the direction of rotation. The resultant current and magnetomotive force in the receiver; coils varies according to the position of the brushes 20, 30 and causes the rotor 63 to assume a position corresponding to the position of shaft I3.

The ratio between the resistance of either of the pair of receiver coils 62 or 64 and the resistance of winding.28 as measured betweenbars 26 and 21"may be of any suitable value, but is preferably of the order of 3.6 to 1 for optimum accuracy of the embodiment illustrated in Fig. 3.

Fig. 4 diagrammatically illustrates another embodiment of this invention, in which only one arcuate bar 21 is used and in which the end turns of a 90 degree resistor segment opposite bar 21 are joined together by a low resistance connector 1|, such as a strip of wire. The terminals of battery 69 are connected to connector H and sector 21 and the operation of the transmitter is similar to that described above forthe embodiment illustrated in Fig.3. For the embodiment illustrated in Fig. 4, the ratio between the resistance of either ofthe pair of receiver coils 62 or 64 and the resistance of winding 28 as measured between bar 21 and connection H may be'of any suitable value, but is preferably of the order of 1.5 to 1 for optimum accuracy.

Although but two'embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention'or from the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

-1, A telemetric resistor transmitter comprising an annular core, a winding of wire of uniform cross section on said core, said winding having a constant number of axially disposed turns per unit of peripheral length, means for insulating each said turn from the adjacent said turn, means forming a low resistance connection between each turn and the adjacent turns of a first 90 degree segment of said resistor for connection to a first terminal of a source of current, means forming another low resistance connection between the end turns of a second 90 degree resistor segment diametrically opposite said first segment for connection to a second terminal of said source, a plurality of equiangularly spaced brushes in contact with said resistor for connection to a receiver, and means for causing relative rotation between said brushes and said resistor in accordance with an indication to be transmitted to supply said receiver with currents which are a measure of said rotation.

2. A telemetric resistor transmitter comprising an annular core, a winding of wire of uniform cross section on said core, said winding having a uniform number of axially disposed turns per unit of peripheral length, means for insulating each said turn from the adjacent said turns, means forming a low resistance connection between each turn and the adjacent turns of a first 90 degree segment of said resistor for con nection to a first terminal of a source of current, means forming another low resistance connection between each turn and the adjacent turns-of a second 90 degree segment diametrically opposite said first segment for connection to a second terminal of said source, a plurality of equiangularly spaced brushes in contact with said resistor for connection to a receiver, and means for causing relative rotation between said resistor and said brushes in accordance with an indication to be transmitted to supply to said receiver currents which are a measure of said rotation.

3. A telemetric resistor transmitter comprising an annular core, a winding of wire of uniform cross section on said core, said winding having a uniform number of axially disposed turns per unit of peripheral length, means for insulating each said turn from the adjacent said turns, means forming a low resistance connection between each turn and the adjacent turns of a first 90 degree segment of said resistor for connection to a first terminal of a source of current, means forming another low resistance connection between each turn and the adjacent turns of a second 90 degree segment of said resistor diametrically opposite said first segment for connection to a second terminal of said source of current, a first pair of brushes in contact with said wire at diametrically opposite points of said resistor for connection to a coil of a receiver, a second set of brushes in contact with said wire displaced 90 degrees from said first set of brushes for connection to another coil of said receiver, and means for causing relative rotation between said brushes and said resistor in accordance with an indication to be transmitted to supply currents to said coils which are a measure of said rotation.

4. A telemetric resistor transmitter comprising an annular core, a winding of wire of uniform cross section on said core, said winding having a uniform number of axially disposed turns per unit of peripheral length, means for insulating each said turn from the adjacent said turns,

means forming "a low resistance connection between each turn and the adjacent turns of a first degree segment of said resistor for connection to a first terminal ofa source of current, means forming another low resistance connection between the end turns of a 90 degree segment of said resistor diametrically opposite said first segment for connection to a second terminal of said source, a first pair of brushes in contact with said resistor at diametrically opposite points of said resistor for connection to a coil of a receiver, a second set of brushes in contact with said wire displaced 90 degrees from said first set of brushes for connection to another coil of said receiver, and means for causing relative rotation between said brushes and said resistor in accordance with an indication to be transmitted to supply currents to said coils which are a measure of said rotation.

5. A telemetric resistor transmitter comprising an annular core, a winding of wire of uniform cross section on said core, said winding having a uniform number of axially disposed turns per unit of peripheral length, means for insulating each said turn from the adjacent said turns, means forming a low resistance connection between each turn and the adjacent turns of a first 90 degree segment of said resistor for connections to a first terminal of a source of current, means forming another low resistance connection between each turn and the adjacent turns of a 90 degree segment of said resistor diametrically opposite said first segment for connection to a second terminal of said source, a first pair of contact making rollers in contact with said wire at diametrically opposite points of said resistor for connection to a coil of a receiver, a second set of contact making rollers in contact with said wire displaced 90 degrees from said first pair of rollers for connection to another coil of said receiver, and means for causing relative rotation between said first and second rollers and said resistor in accordance with an indication to be transmitted to supply currents to said coils which are a measure of said rotation.

6. A telemetric resistor transmitter comprising two terminals, an annular core, a winding of wire of uniform cross section on said core, said winding having a uniform number of axially disposed turns per unit of peripheral length, means for insulating each said turn from the adjacent said turns, means forming a low resistance connection between each turn and the adjacent turns of a first 90 degree segment of said resistor connected to one said terminal, means forming another low resistance connection between each turn and the adjacent turns of a 90 degree segment of said resistor diametrically opposite said first segment connected to the other said terminal, a first pair of brushes in contact with said wire at diametrically opposite points of said resistor for connection to a coil of a receiver, a second set of brushes in contact with said resistor displaced 90 degrees from said first set of brushes and connectable to another coil of said receiver, supporting means for said brushes, means for causing rotation of said resistor in accordance with an indication to be transmitted, and contact means mounted on said supporting means connectable to a source of current and continuously engaging said terminals as said rotation takes place for supplying current to said resistor.

CHARLES R. MIKOLIC.

(References on following page) Number '7 REFERENCES: CITED *The fllowmg references are or recordin'the Number me of this patent: 2,556 :Ummn'smms'm'mms 724,380

' Name Date 2,300,220 Hempel Oct. 27. 1942 8 IEOREIGN PATENTS Country Date Austria, June 10, 1910 Germany Aug. 25, 1942 

